//提供各种混合
.self-center(@pos:absolute) {
	position: @pos;
	left: 50%;
	top: 50%;
	transform: translate(-50%, -50%);
}

.self-fill(@pos:absolute) {
	position: @pos;
	left: 0;
	top: 0;
	height: 100%;
	width: 100%;
}
